One example of bodymaker is that used for the production of thin-walled metal cans by the so-called “drawing and wall-ironing” (DWI) process. In a DWI process, a flat circular blank of metal is drawn through one or more drawing dies to form a shallow cup. The cup is then mounted on the free end of a punch which extends from a reciprocating ram, and the cup wall is then “ironed” by passing through one or more ironing dies to lengthen the side wall of the cup and form a can. Clearly it is important to the ironing process that the ram (and punch) are aligned with the bore of the dies if the ironing is to be controlled over repeated cycles.
In order to drive the ram for the reciprocating action, the ram is connected to a slide block of the bodymaker. In known bodymakers, the ram has a flange at one end to allow it to be clamped to the slide block using a clamp ring. This is generally referred to as the “back” end of the ram. The front end of the ram has the punch attached to it. The ram is supported at its opposite (rear) end in a ram guide bush assembly, which includes seals for containing lubricant/hydraulic fluid.
The clamp ring and flange, which secure the ram to the slide block, have a larger diameter than the bore of the bush assembly. Consequently, if the ram needs to be removed, for example to change a set of seals, the ram has to be removed from the rear of the machine. This involves significant “down-time” (several hours) for dismantling the machine to remove the slide block and ram, as well as the time required for subsequent re-alignment of the ram when reassembling. This invention seeks to provide a solution to this problem.